Chinese authorities have stepped up rescue efforts after an earthquake Thursday injured at least 29 people in southwest China's Yunnan Province.

The 5.1-magnitude quake struck the border of Lufeng and Yuanmou counties in Chuxiong Yi Autonomous Prefecture at 12:56 p.m.

As of midday Friday, four counties - Lufeng, Yuanmou, Muding and Wuding - had reported injured residents, the local government said in a statement.

The statement said at least 100 schools, 72 hospitals and thousands of homes were damaged in the quake.

The provincial and local governments earmarked 6 million yuan (882,353 U.S. dollars) for relief funds Thursday. Thousands of tents were delivered to the quake-hit areas overnight, along with quilts, clothing, food and drinking water.

The People's Liberation Army's Chengdu Military Area Command has sent more than 700 soldiers to help in the rescue.

By Friday morning, the soldiers had evacuated more than 3,000 residents from damaged homes to tents. They also dismantled nearly 100 perilously-standing buildings, lest they collapse and cause further casualties.

By 10 a.m. Friday, 37 aftershocks had occurred in the area, the strongest of which measured over 5-magnitude, the provincial seismological center said.

A disaster prevention official Friday dispelled public fears the quake was a consequence of the prolonged drought plaguing southwest China.

"There's no clear evidence that earthquakes follow severe drought or flood, even though some elderly people believe so," said Yunnan Provincial Earthquake Administration officer Gu Yishan.

He said the quake-affected areas had suffered several tremors in December and January, but that all measured under 4.9 magnitude.

Yunnan Province is suffering the worst drought in 60 years. In some counties, reservoirs, ponds and wells have gone dry. Almost 6 million people and 3.6 million head of livestock are facing drinking water shortages.

The drought has also ravaged neighboring Guizhou Province and Guangxi Zhuang Autonomous Region.